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author | Felix Mulder <felix.mulder@gmail.com> | 2016-05-25 12:50:36 +0200 |
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committer | Felix Mulder <felix.mulder@gmail.com> | 2016-05-26 13:20:10 +0200 |
commit | fc419f55e29b7e77e9062d40a0864086f8d51bfa (patch) | |
tree | 70d1420157c4bd5cd4cd3613bcbc7e13a1cfa113 /src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala | |
parent | 6b48e990d7e7d59cc5a67942a455eadcd9f4570f (diff) | |
download | dotty-fc419f55e29b7e77e9062d40a0864086f8d51bfa.tar.gz dotty-fc419f55e29b7e77e9062d40a0864086f8d51bfa.tar.bz2 dotty-fc419f55e29b7e77e9062d40a0864086f8d51bfa.zip |
Don't evaluate isInstanceOf for value classes, disable bugged tests
The tests `i1059.scala` and `t3480.scala` are failing due to a bug
in pattern matcher that evaluates the `x` in `List(x: _*)` incorrectly.
Concerned issue: #1276
Diffstat (limited to 'src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala')
-rw-r--r-- | src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala | 63 |
1 files changed, 36 insertions, 27 deletions
diff --git a/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala b/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala index 8b1baa11a..14c3dea71 100644 --- a/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala +++ b/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala @@ -5,7 +5,7 @@ import dotty.tools.dotc.util.Positions._ import TreeTransforms.{MiniPhaseTransform, TransformerInfo} import core._ import Contexts.Context, Types._, Constants._, Decorators._, Symbols._ -import TypeUtils._, TypeErasure._ +import TypeUtils._, TypeErasure._, Flags._ /** Implements partial evaluation of `sc.isInstanceOf[Sel]` according to: @@ -25,10 +25,11 @@ import TypeUtils._, TypeErasure._ * * 1. evalTypeApply will establish the matrix and choose the appropriate * handling for the case: - * 2. a) handleStaticallyKnown - * b) falseIfUnrelated with `scrutinee <:< selector` - * c) handleFalseUnrelated - * d) leave as is (aka `happens`) + * 2. a) Sel/sc is a value class or scrutinee is `Any` + * b) handleStaticallyKnown + * c) falseIfUnrelated with `scrutinee <:< selector` + * d) handleFalseUnrelated + * e) leave as is (aka `happens`) * 3. Rewrite according to step taken in `2` */ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer => @@ -43,43 +44,43 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer => * the correct warnings, or an error if statically known to be false in * match */ - def handleStaticallyKnown(tree: Select, scrutinee: Type, selector: Type, inMatch: Boolean, pos: Position): Tree = { + def handleStaticallyKnown(select: Select, scrutinee: Type, selector: Type, inMatch: Boolean, pos: Position): Tree = { val scrutineeSubSelector = scrutinee <:< selector if (!scrutineeSubSelector && inMatch) { ctx.error( s"this case is unreachable due to `${selector.show}` not being a subclass of `${scrutinee.show}`", Position(pos.start - 5, pos.end - 5) ) - rewrite(tree, to = false) + rewrite(select, to = false) } else if (!scrutineeSubSelector && !inMatch) { ctx.warning( s"this will always yield false since `${scrutinee.show}` is not a subclass of `${selector.show}` (will be optimized away)", pos ) - rewrite(tree, to = false) + rewrite(select, to = false) } else if (scrutineeSubSelector && !inMatch) { ctx.warning( s"this will always yield true if the scrutinee is non-null, since `${scrutinee.show}` is a subclass of `${selector.show}` (will be optimized away)", pos ) - rewrite(tree, to = true) - } else /* if (scrutineeSubSelector && inMatch) */ rewrite(tree, to = true) + rewrite(select, to = true) + } else /* if (scrutineeSubSelector && inMatch) */ rewrite(select, to = true) } /** Rewrites cases with unrelated types */ - def handleFalseUnrelated(tree: Select, scrutinee: Type, selector: Type, inMatch: Boolean) = + def handleFalseUnrelated(select: Select, scrutinee: Type, selector: Type, inMatch: Boolean) = if (inMatch) { ctx.error( s"will never match since `${selector.show}` is not a subclass of `${scrutinee.show}`", - Position(tree.pos.start - 5, tree.pos.end - 5) + Position(select.pos.start - 5, select.pos.end - 5) ) - rewrite(tree, to = false) + rewrite(select, to = false) } else { ctx.warning( s"will always yield false since `${scrutinee.show}` is not a subclass of `${selector.show}`", - tree.pos + select.pos ) - rewrite(tree, to = false) + rewrite(select, to = false) } /** Rewrites the select to a boolean if `to` is false or if the qualifier @@ -106,25 +107,30 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer => val scrutinee = erasure(s.qualifier.tpe.widen) val selector = erasure(tree.args.head.tpe.widen) - val scTrait = scrutinee.typeSymbol is Flags.Trait + val scTrait = scrutinee.typeSymbol is Trait val scClass = scrutinee.typeSymbol.isClass && - !(scrutinee.typeSymbol is Flags.Trait) && - !(scrutinee.typeSymbol is Flags.Module) + !(scrutinee.typeSymbol is Trait) && + !(scrutinee.typeSymbol is Module) - val scClassNonFinal = scClass && !scrutinee.typeSymbol.is(Flags.Final) - val scFinalClass = scClass && (scrutinee.typeSymbol is Flags.Final) + val scClassNonFinal = scClass && !(scrutinee.typeSymbol is Final) + val scFinalClass = scClass && (scrutinee.typeSymbol is Final) - val selTrait = selector.typeSymbol is Flags.Trait + val selTrait = selector.typeSymbol is Trait val selClass = selector.typeSymbol.isClass && - !(selector.typeSymbol is Flags.Trait) && - !(selector.typeSymbol is Flags.Module) + !(selector.typeSymbol is Trait) && + !(selector.typeSymbol is Module) - val selClassNonFinal = scClass && !(selector.typeSymbol is Flags.Final) - val selFinalClass = scClass && (selector.typeSymbol is Flags.Final) + val selClassNonFinal = scClass && !(selector.typeSymbol is Final) + val selFinalClass = scClass && (selector.typeSymbol is Final) // Cases --------------------------------- + val valueClassesOrAny = + ValueClasses.isDerivedValueClass(scrutinee.typeSymbol) || + ValueClasses.isDerivedValueClass(selector.typeSymbol) || + scrutinee == defn.ObjectType + val knownStatically = scFinalClass val falseIfUnrelated = @@ -137,13 +143,16 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer => (scTrait && selClassNonFinal) || (scTrait && selTrait) - val inMatch = s.qualifier.symbol is Flags.Case + val inMatch = s.qualifier.symbol is Case - if (knownStatically) + if (valueClassesOrAny) tree + else if (knownStatically) handleStaticallyKnown(s, scrutinee, selector, inMatch, tree.pos) else if (falseIfUnrelated && scrutinee <:< selector) + // scrutinee is a subtype of the selector, safe to rewrite rewrite(s, to = true) else if (falseIfUnrelated && !(selector <:< scrutinee)) + // selector and scrutinee are unrelated handleFalseUnrelated(s, scrutinee, selector, inMatch) else if (happens) tree else tree |